Such a navigation technique has for example been described in principle in DE 196 39 615 C2.
Combining transillumination and/or tomographic image capture image data and video images and/or actual images is also already known in principle, for example from EP 1 321 105 B1 or EP 0 685 088 B1 and from superimposing virtual image material in images of surgical microscopes. In these conventional image output methods, guidance is performed primarily on the basis of the data which can be visually captured, i.e. primarily on the basis of a “visual reality”, while “virtual image data”—i.e. image data from medical imaging methods performed beforehand or during navigation—serves only as a second source of information, i.e. as a secondary, supplementary image data source. Thus, in accordance with the prior art, the image which can be captured visually, i.e. by the human eye or by the human eye with the assistance of cameras or object lenses, is merely augmented with the aid of the imaging data (CT, MR, x-ray, etc.), which incurs a number of disadvantages. In addition to the relatively marginal utilization of the virtual image material, access to the region of interest has to be uncovered when using a microscope, which makes the method more significantly invasive. If an endoscope is used, this forms a second instrument which additionally has to be controlled and checked and which in principle can also disrupt the freedom of movement of the treatment instrument.